What is the planned status of Multiarch support in 11.10? In AMD64 Alpha 1, I attempted to install the i386 google chrome package using dpkg. The install failed citing architecture mismatches, Is support for this kind of install planned or am I missing something?

Multiarch is supported pretty well at this point (last time I tried was Beta 1). It's just that a package must be build with support for Multiarch. You can see whether a package was built for Multiarch by checking it dependencies for the multiarch-support package.